Extra-air valve for internal-combustion engines



R. E. BURCH EXTRA AIR VALVE-FOR INTERNAL COMBUSTION ENGINES Sept. 15,1925 1,553,668;

Filed Ana. 4, 1924 fltiorney.

Patented Sept. 15, 1925.

UNITED STATES "PATENT OFFICE.

ROBEBT ERNEST BURCH, or KENSINGTON, LONDON, ENGLAND.

EXTRA-AIR VALVE FOR INTERNAL-COMBUSTION ENGINES.

Application filed August 4, 1924. Serial No. 729,923.

in accordance with the advance or retardation of the ignition. For this purpose it has been proposed to employ an auxiliary or extra air inlet valve so connected with the ignition-control mechanism that as the latter is moved from the spark-retard position to the spark-advance position the auxiliary air valve is progressively opened. The object of the present invention is to provide an improved device of this character, such,- that, whereas no extra air will be admitted so long as the ignition remains at zero, nor will any admission of extra air take place during any advance of the point of ignition from zero to half advance, extra air will be admitted in a progessively increasing proportion from nil to a maximum in accordance with the gradual advance of the point of ignition from half advance to normal full advance, whilst such maximum admission of extra air will be maintained during any further advance of the ignition to its earliest point, and conversely as the ignition is retarded.

For this purpose, according to the invention, there are employed, in combination, an arm upon the ignition-control rod, and a lever constantly tending under spring-action to open the extra air admission valve,- the arrangement, relative proportions, and paths of said arm and lever being such that (a) during movement of the ignition-control during the converse movement said arm will cause the lever to close the valve, and

that (0) during any further movement of the ignition-control rod, beyond the position corresponding to normal full advance, in the direction to advance the point of ignition, the arm on said rod will permit the lever to hold the valve fully open. I i In the accompanying drawings, Figures 1 and 2 are elevations, viewed at right angles to one another, of' a rotary plug-tap for regulating the admission of extra air to the intake of an internal combustion engine, showing theapplication thereto of one arrangement embodying'the present invention,

, In the example illustrated, therotary plug a of the air-tap b (the connections to which are not shown) is provided with a lever 0 whereby the angular position of the plug is controlled; the plug constantly tending to assume the fully-open position (in which it is shown) under the influence of a spring at I interposed in tension between the lug e on the lever 0 and an abutment f on the body of the tap. The axis of the plug 0: extends in the same plane as and substantially parallel to the axis of the rotary ignition-control rod 9 (a small part only of which is shown) and upon the rod 9 is adjustably clamped an arm h which, as the rod 9 is turned about its axis to advance or retard the point of ignition, moves through an are which intersects the arc of movement performed by the lever 0 in opening and closing the tap b.

The extremity j of the arm h, which may be provided with a suitable wearing-surface as indicated, bears against that side of the lever 0 towards which the latter is drawn by the spring (Z; the arrangement being such that, when the rod 9 is turned from the angular position corresponding to normal full advance (shown in Figure 1 in full lines) to that corresponding to zero advance (shown at 00 in dot-and-dash lines),

the lever'c will be caused to move from the fully-open position (shown inFigure 1 in full lines) to the fully-closed position (shown in dot-and-dash lines) against the stress of the spring d whereas, when the rod 9 is turned in the reverse direction from the position a corresponding to zero advance to that corresponding to normal full advance, the lever 0 will be allowed to move under the stress of the spring d so as to open the tap. That portion is of the lever 0 against which the extremity j of the arm It bears, is so inclined tangentially with reference to the axis of the plug a that, as the rod 9* is turned from the zero position :12 to the intermediate position :1 corresponding approximately to half ignition, the plug a will remain in .the closed position, a supply of extra air not being required until the point of ignition is advanced still further towards normal full advance.

The position 2 of the arm h, shown in Figure 1 in dot-and-dash lines, corresponds to an angular position to which, in some cases, the rod 9 may be capable of being brought when it is required to accelerate the ignition to the utmost extent; in which circumstances no corresponding increase in the quantity of extra air admitted is re quired, so that the arm h then moves out of contact with the lever c which remains in the position corresponding to fullopening of the tap b.

I claim 1"? In an internal-combustion engine whereof the intake is provided with a valve for regulating the admission of extra air, the combination with an arm upon the ignitioncontrol rod, of a lever constantly tending under spring-action to open said valve; the arrangement, relative proportions, and paths of said arm and lever being such that (a) during movement of the ignition-control rod in either direction between the positions corresponding respectively with Zero advance and half advance, the arm on said rod will prevent movement of the lever in the direction to cause the valve to open, that (7)) during progressive movement of the ignition-control rod from the position corresponding to half advance to that corresponding to normal full advance, the arm on said rod will permit the lever to open the valve gradually to its fullest extent, and during the converse movement said arm will cause the lever to close the valve, and that (a) during any further movement of the ignition-control rod, beyond the position corresponding to normal full advance, in the direction to advance the point of ignition, the arm on said rod will permit the lever to hold the valve fully open, substantially as described.

ROBERT ERNEST BURCH. 

